Improvement in trusses



H. A. KIMBALL.

TRUSS .PatentedrNom 23,1875.

Wagga? N. PETERS, HDTO-LITHOGRFHER.

UNITED STATES PATENT QFFICE.

`HIBAM A. KIMBALL, `OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T() BENJAMINC. EVERETT, OF SAME PLACE.

IMPROVEMENT IN l'RUSSVES..

Specication forming part of Letters Patent No. 170,27 3, dated November23, 1875; application tiled November 5, 1875.

To all whom it may concern Be it known that I, HrRAM A. KIMBALL, of thecity and county of Philadelphia, in the State of Pennsylvania, haveinvented a new and useful Improvement in Trusses, ot' which thefollowing is a specification, reference being had to the accompanyingdrawings.

My invention, in the rst place, consists in curving the springcrosswise, commencingr to curve at the ends, where the spring isattened, gradually increasing the curve to the middle ot' the length ofthe spring, whereby to gradually increase its stiffness thereto. In thesecond place, the invention consists in the combination of thepad-holder with 011e end ot' the spring, by means of a swivel connectedwith an adjustable slide, whereby the slide-holder is adjustable in twodirections at right angles to each other. It is held in its adjustedposition by means of set-screws, as hereinafter described.

ln the accompanying drawings, Figure l is a top ricw ot' the spring A,having a padholder, C, in connection therewith. Fig. 2 is a front viewof the same. Fig. 3 is a cross section ot' the pad-holder C and springA, at the line mxot Fig. l. Fig. 4 is -a crosssection of the spring A atthe line yy ot' Fig. l.

Like letters of reference in all the figures indicate the same parts. I

A is the spring, which is curved laterally except a short distance atits ends, where itis iat. The curvature commences at these nat parts,very slightly and gradually increases to the middle of the springs,whereby to i11- crease its stiffness in the middle.

In Fig. 4, which is taken at the point 2, the curvature, it will beseen, is much less than at the point 3, the middle of the spring. Thecurvature has gradually increased from the other end ot' the spring toits middle or point 3, in the same manner. At this point' the spring hassuch a curvature, taken in connection with the thickness of metal, as isrequisite to give it the proper stiffness, and as the curvaturegradually decreases from the middle of the spring to its ends,sensitiveness in the pressure of these resilient parts is effected. Or,in other words, the leverage of the length ot' the spring is balanced bythe' change of l curvature, and thereby sufficient strength is given tothe spring by the curvature with a minimum weight ot' material.

B is a slide on one end of the spring A, to which the pad-holder C isattached. The slide is fastened in its adjusted -position by means ofthe set-screw D. The lower end of the slide is slotted vto receive theflattened part ot' the pin F, which is connected with the cheeks a a bymeans of the joint-pin b. The pad-holder O turns on the rounded part atd ofthe pin F, as a lateral adjustment is given it either to the rightor left. It is held in its adjusted position by means of the set-screwyH, which vpasses through the head or flange f of the pin F. g

For increasing or decreasing the pressure ot' the pad, the holder C isadjusted by means of v the set-screw I, the end ot which bears upon theslide B, as seen in Fig. 3.

I claim as my inventionl. The spring A, having a gradually-increasedlateral curvature from its ends to the middle thereof, whereby togradually increase the stiffness of thespring to that point, to balancethe strength of the leverage of the spring by the change ot' curvature,substantially as set forth.

2. The combination ot' the pad-holder C, slide B, pins F and 71, andset-screws H and l, for an inward, outward, and a lateral adjustment ofthe pad-holders, substantially as set forth.

HIRAM A. KIMBALL.

Witnesses:

THOMAS J. BEWLEY, STEPHEN UsTIoK.

